Method of producing decorated aluminum articles



Oct. 12, 1954 METHOD Filed Feb. 7, 1952 MEN-r INVENTOR Robert E. JohnsonPatented Oct. 12, 1954 METHOD OF PRODUCING DECORATED ALUMINUM ARTICLESRobert E. Johnson, Water-town,

Conn., assignmto Scovill Manufacturing Company, Waterbury, Conn, acorporation of Connecticut Application February 7, 1952, Serial No.270,390

3 Claims. 1

This invention relates to decorated aluminum articles and an improvedmethod of producing the same. When reference is made in thespecification and claims to aluminum it is understood that the materialmay be any Suitable aluminum alloy having a predominant proportion ofaluminum.

The primary object of my invention is to provide an aluminum articlewith a surface decorated with one durable base color which serves as afield to receive an intaglio design havin a durable contrasting color.

A further object is to provide an improved method of producing sucharticles economically without the necessity of applying masks or resiststo cover the designs.

My invention further provides a method whereby the fine or intricatedesigns of the intaglio type can be colored to contrast to the basesurface.

In the drawings I have shown for purposes of illustration one example ofan article made according to my invention and certain steps in themethod of producing the same.

In the drawings:

Fig. 1 is aplan view of the top of a vanity box made accordin to myinvention.

Fig. 2 is a greatly enlarged fragmentary section of the surface portionof an aluminum article such as a vanity box cover after the first stepin my improved process.

Fig. 3 is an enlarged fragmentary section of same after the intagliodesign has been cut on its surface.

Fig. 4 is a view similar to Fig. 3 showing the intaglio design anodized.

Fig. 5 is a view similar to Fig. 4 showing the coating lined to indicatea contrasting color, and

Fig. 6 is an enlarged cross section of the edge of the cover as it wouldappear anodized but without the dye or intaglio design.

As one example of the invention I have shown the cover of a round vanitybox 10 formed from sheet aluminum ll. The cover It) is first anodicallytreated to provide the usual oxide surface known as anodizing, whichbuilds up a protective coatin [2 on the aluminum sheet II. This oxidecoating being porous may be treated by immersion in a dye solution toprovide the desired base color indicated by the added cross lines 13, orif it is desired that the base be of natural aluminum this step may bedispensed with. The next step in the improved process is to seal thisporous surface oxide coating 12 so as to make it impervious to anyfurther coloring by a dye solution. If the base color is desired to benatural aluminum this treatment can be accomplished by immersion in hotWater for a suflicient length of time, but if the surface coating l2 hasbeen treated with a dye l3 the sealing operation is preferably carriedout by immersion in a heated dilute solution of nickel acetate. Thissealed surface of the oxide coating is indicated by the heavy top lineM. This treatment does not bleed out the dye from the surface coatingwhen the article is given any subsequent anodizing and/or dyeingtreatment.

The next step in the process is to mechanically cut through the dyedanodized surface coating l2 and into the aluminum material as indicatedat I5 either by an engine turning operation or by an engraving operationto any prescribed design. In either case the cutting operation isperformed by what may be termed an edge cutting tool. One such design isshown in Fig. 1, and a sectional view of a portion of the cover is shownin Fig. 3 on a greatly enlarged scale.

In view of the fact that the initial anodic treatment has deposited anoxide coating l2 over the entire article, and since such an oxide coatinis not a good electrical conductor, I select a portion of the articlewhich will not be exposed when finished, and remove a small portion ofthe oxide coating therefrom so that a good electrical contact can againbe made therewith. As specifically shown in Fig. 6 in the vanity boxcover It I select a spot on the inside of the cover flange as at Hi toremove a small section of the anodic surface coating l2 down to theoriginal aluminum surface. This is for the purpose of re-anodizing whichis the next step. This provides an oxide coating I! on the surfaces ofthe aluminum in the cut design portion only without affecting the basesurface or its color treatment. It is now possible to dye the oxidizedsurfaces of the design merely by immersin them a second time in anydesired contrasting color, as indicated by the added cross lines in Fig.5.

Finally, the dye surfaces of the design are preferably sealed by aprocess similar to the first sealing operation as indicated by heavyline I8 in Fig. 5. If it is desired to have one portion of a design onecolor and another portion a different color it is merely necessary torepeat the latter part of the process.

7 As a result of my invention for the first time some very beautiful andintricate design effects can be produced on the surfaces of aluminumarticles and provided with a very hard and durable finish at a veryreasonable cost as compared to anything of this kind known to have beendone before.

I claim:

1. The method of decorating an exposed surface of an aluminum articlewhich includes depositing an oxide coating over the entire surface byanodic treatment, sealing said oxide coating to render it impervious todyes, then mechanically cutting through the oxide coating and into thealuminum material by an edge cutting tool to a prescribed intagliodesign, re-anodizing said article to deposit an oxide coating on saidout surfaces and dyeing said second oxide coating to provide a color inthe design contrasting with the color of the remainder of said surface.

2. The method as defined in claim 1 wherein subsequent to the firstanodic treatment and prior to the sealing operation, said surface isdyed to the desired color.

3. The method defined in claim 1 wherein subsequent to the first anodictreatment and prior to the sealing operation the oxide coating is dyedto the desired color and wherein the sealing operation comprisesimmersing the article in a dilute solution of nickel acetate.

References Cited in the file of this patent UNITED STATES PATENTS OTHERREFERENCES The Metal Industry, June 18, 1943, pages 386- 388.

1. THE METHOD OF DECORATING AN EXPOSED SURFACE OF AN ALUMINUM ARTICLEWHICH INCLUDES DEPOSITING AN OXIDE COATING OVER THE ENTIRE SURFACE BYANODIC TREATMENT, SEALING SAID OXIDE COATING TO RENDER IT IMPERVIOUS TODYES, THEN MECHANICALLY CUTTING THROUGH THE OXIDE COATING AND INTO THEALUMINUM MATERIAL BY AN EDGE CUTTING TOOL TO A PRESCRIBED INTAGLIODESIGN, RE-ANODIZING SAID ARTICLE TO DEPOSIT AN OXIDE COATING ON SAIDCUT SURFACES AND DYEING SAID SECOND OXIDE COATING TO PROVIDE A COLOR INTHE DESIGN CONTRASTING WITH THE COLOR OF THE REMAINDER OF SAID SURFACE.